Inorganic Chemicals Industry ›› 2022, Vol. 54 ›› Issue (9): 96-101.doi: 10.19964/j.issn.1006-4990.2021-0741

• Research & Development • Previous Articles     Next Articles

Study on preparation of food?grade potassium chloride by one?step adsorption and purification

DU Bingxuan(),LI Haichao(),LIN Zezhong   

  1. Qinghai Minzu University;Institute of Resource Chemistry of Qinghai,Xining 810007,China
  • Received:2021-11-23 Online:2022-09-10 Published:2022-09-22
  • Contact: LI Haichao E-mail:tangchaolizi_225@sina.com;lihaichao@vip.163.com

Abstract:

The industrial potassium chloride produced by Qinghai Salt Lake has flotation agent residues and heavy metals exceeding the standard.Purification of industrial potassium chloride for use as food grade potassium chloride will yield significant economic benefits.Fish scale activated carbon was prepared by activation method using waste fish scale as raw material.Using fish scale activated carbon as adsorbent,food grade potassium chloride could be obtained by simultaneously removing heavy metal lead ions[Pb(Ⅱ)] and organic amines from industrial potassium chloride insalt lake by one?step adsorption method.The results showed that fish scales were firstly pretreated by boiling and phosphoric acid impregnation,and then calcined at 550 ℃ to obtain fish scale activated carbon with a specific surface area of 496.152 m2/g.In the purification of industrial potassium chloride from fish?scale activated carbon,ion?exchange adsorption dominated its adsorption of Pb(Ⅱ),while electrostatic interactions and van der Waals interactions played an important role in its adsorption of octadecylamine.When the dosage of fish scale activated carbon was≥7 g/L,the contents of heavy metal Pb(Ⅱ) and organic amines in purified industrial potassium chloride were in accordance with the requirements of GB 25585—2010“Food Additives Potassium Chloride”.The one?step adsorption method of activated biochar was realized to prepare food grade potassium chloride from industrial potassium chloride in salt lake.

Key words: potassium chloride, salt lake, adsorption, activated carbon

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